Bibcode
in't Zand, Jean; Markwardt, Craig; Santos-Lleo, Maria; Bazzano, Angela; Cocchi, Massimo; Cornelisse, Remon; Heise, John; Kuulkers, Erik; Natalucci, Lorenzo; Sanchez-Fernandez, Celia; Swank, Jean; Ubertini, Pietro
Bibliographical reference
American Physical Society, April Meeting, Jointly Sponsored with the High Energy Astrophysics Division (HEAD) of the American Astronomical Society April 20 - 23, 2002 Albuquerque Convention Center Albuquerque, New Mexico Meeting ID: APR02, abstract #N17.103
Advertised on:
4
2002
Citations
0
Refereed citations
0
Description
Thanks to dedicated X-ray monitoring observations of the Galactic bulge
with the Wide Field Cameras on BeppoSAX, several tens of faint X-ray
transients have been discovered with peak fluxes that are just a few
percent of that of classical X-ray novae. Most of these faint transients
exhibit type-I X-ray bursts and, thus, harbor a neutron star. A few
cases do not, like SAX J1711.6-3808 which was active between January and
May 2001. We followed up this transient with BeppoSAX, RXTE and
XMM-Newton. The 1-200 keV spectrum is characterized by Comptonization, a
transient soft excess and a 2.6 keV (FWHM) broad emission feature at the
Fe-K line complex whose flux peaks in tandem with that of the soft
excess. The emission feature is reminiscent to that seen in the
classical black hole candidate Cyg X-1. We propose that SAX J1711.6-3808
contains a black hole, and that the broadness of the emission feature is
related to Doppler shifts due to orbital motion of the emitting material
around the compact object. This would be the 4th time that a broad Fe-K
emission feature has been detected in a Galactic black hole.